Maybe you only drink a certain type of coffee cause of the ethical reasons of the company, or maybe you use a certain technique because you are a person who likes doing things the ‘right way’. Or whatever you like to tell yourselves at least.

One major problem I have with snobby people is when they act like they know everything, and then put others down because of it. Especially because half the time people are just making stuff up anyway.

Take the example of wine.

It’s been shown that when ‘experts’ try wines that a lot of the time they don’t know what they are talking about.

We all have that friend that brings round the ‘fancy’ wine when all you really want to do is to down the bottle to forget the week you’ve just had.

There was a study a few years ago that basically dyed the colour of the wine that the experts were tasting. These people got thrown off by these visual cues and described what they were seeing rather than the wine they were drinking.

This adaptation comes about as it is quicker for us to register threats when they are visually coming at us rather than smelling or hearing them.

But we are getting off track.

Science doesn’t have an exact definition or description of what it means to be a snob. We can somewhat agree however that it is some form of people thinking they are better than others for some reason or other.

I’m not normally a hipster…. I swear.

It is not only privileged people either who can exhibit this kind of behaviour. ‘Ingroup-outgroup bias’ can show the opposite where people who have less feel superior to those who have more.

This kind of snobbery needs others for it to occur though, so if you don’t feed into it then it will help reduce this. You know you aren’t inferior because you like instant coffee so don’t live up to that stigma. Own that instant gurl!

People get so hung up on how their coffee is that they forget the simple thing – it’s a nice drink, it’s social, warming and just damn tasty. Does it really matter where/how you get it??

So with that, I am now officially finished with my weekly blogging. I hope you enjoyed reading along and learning more with me. Next time you are enjoying a warm cuppa, think back to some fun science and the fact that it doesn’t matter who you are or what kind you are drinking, the coffee will always be tasty.

Many people are addicted to their daily (or 3x daily) cup of coffee. You know when to avoid that person who is trying to reduce their caffeine intake. They are irritable, tired, anxious and just an all round horrible person to be around.

Gotta keep that caffeine intake up or watch out for Mr Grumps

Why does this happen and is coffee really truly addictive?

Prepare once more to… SCIENCE!

As we touched on briefly a few weeks ago – when you drink coffee the caffeine takes the places of that beautiful sleepy adenosine and means you have to eventually work harder and drink more coffee to keep your caffeine taking their place.

However, caffeine also helps increase the production of the dopamine and adrenaline inside your brain. Dopamine is a neurotransmitter, which basically makes you feel good and stimulates you. It works to control your brain’s reward and pleasure centres.

Chemical structure of dopamine.

Because caffeine produces this good feeling inside of you, it means you just want to feel this way again and so you keep wanting to have it.

Dopamine is what helps coffee act as a stimulant as well. This acts as a stimulant to the central nervous system. However, there are other drugs that also work as stimulants, which lead to far bigger problems, like the drugs meth and ecstasy.

I’m sorry to say, I have bad news for you. No one actually knows the real reason that you get that urge to poop after your morning cuppa. However, there are some ideas floating around so I’m going to take you through some of these.

Studies have shown that only minutes (four to be exact) after having your morning coffee that your body starts to get moving. Again, no one is 100% sure why this happens. We know it isn’t due to the caffeine though, as the same effect has been seen when people drink non-caffeinated beverages.

Whatever it is in the coffee though, seems to activate your lower colon (also known as your distal colon). The coffee stimulates the productions of a hormone called gastrin, which is made in your tum. This hormone makes your stomach produce more acid which is a signal to your body that there are things to get rid of in there. It also seems to cause contractions of your stomach and intestines which has the same effect again.

What is totally inside your body right now (and reacting to that coffee you just had).

You may think that drinking more coffee would cause you to eventually lose all control of your digestive system, but actually, the more coffee you drink the less this effect is seen. Not only this but regular coffee drinkers also become immune to the diuretic effect (coffee=peeing) and don’t pee anymore than non-coffee drinkers.

These results may also be due to a psychological effects of your daily routine. Say you get up in the morning and drink a cup o’ coffee and then need to poop – this could be solely down to the time of day and your everyday routine rather than the actual coffee in hand.

I’m hoping no one is using this as toilet reading material…

It’s also important to remember that milk can have this effect too on people who are intolerant to dairy – so this can be the cause in some people.

So, there you have it. Even if coffee doesn’t have this laxative effect on you – you know more now than you did four minutes ago.

So, we know where the bean comes from, but have you ever been curious on how it gets from that green bean in the wild to the delicious brown bean that is used for your morning coffee?

This happens by coffee roasting, which is different to the trend going round at the moment where you roast your friends. Coffee roasting is where the beans are subjected to extreme heat and heated until they turn that perfect shade of brown (which can change depending on what flavour you want to go for).

Not the type of roasting that we are talking about…

The process begins as an endothermic reaction. This just means that the reaction absorbs heat. At this stage the beans are dried slowly until they begin to smell – this will normally smell like popcorn or toast. People from Dunedin will be very familiar with this smell, as the Greggs factory wafts its burnt toast smell across town – especially bad on my side of uni (apparently there have even been concerned people in the department who think a fire has started).

Coffee Roasting

After this smell begins to occur, the next step known as ‘the first crack’ happens at about 205°C. During this stage, the bean become a lighter brown colour, double in size (due to carbon dioxide loss) but loses about 5% of its weight.

The beans lose their green colour through this process due to the breakdown in their chlorophyll and well as the Maillard reaction. This is a chemical reaction between amino acids and sugars which end up producing flavour compounds and melanoidins (which also contribute to that lovely brown colour).

Anyway, back to the roasting. The temperature is then increased to about 220°C. The bean loses more of its weight – about 13% and the colour changes to a darker colour.

This process is called pyrolysis. This is the decomposition of organic material and is basically what happens to all your food when you cook it and is also responsible for the colour of the roasted bean.

Different coffee roasts – Taken by Jessica Spengler

The next step is exothermic (the heat is released) and then the second crack occurs. The bean gets darker still and the temperature gets cranked up to bout 225-230°C. This is when the beans get their oily outer layer.

Depending on how long the roasters leave the bean in during this process will alter the type of roast they will get in the end. The degree of the roast will change the flavours that come through from the bean.

A week or to ago I explained the effects that caffeine has on your brain and body. However, there are certain people who can not handle the effects of caffeine and instead drink coffee for the pure delicious taste rather than its fantastic ability to get you through your day.

But how exactly do you get the caffeine out of the coffee bean?

Prepare to science!!

The decaffeination process starts off the same way no matter which method you use, with the bean in its green, non-roasted state.

Basically this method submerges the beans in very hot water – think of a spa but for coffee – which washes off the caffeine. The beans are then put through an activated charcoal filter. This filter stops the caffeine particles from moving through but the smaller particles like the oils and flavours are free to flow. These old beans are then thrown away and this flavour rich water (green coffee extract) is used to wash away the caffeine on new beans while maintaining the flavour. This is because there is already the flavour particles in the water so the ones inside the beans have no where to go – it’s too crowded out there for them so they just to stay at home. All together this takes about 8-10 hours.

This method requires the beans to be steamed for 30 minutes which helps to open their pores (again, sounds like a lovely day at the spa). Then to remove the caffeine the beans are then rinsed with dichloromethane or ethyl acetate for around 10 hours. The solvent is then removed and the beans are steamed once again to get rid of any of the leftover solvent.

A green bean enjoying the steaming process

Some people are concerned about the use of solvent in their coffee beans – however there is only one part per million of the actual solvent used and it is also very unlikely to survive the roasting process.

In this process the C02 (carbon dioxide) works to remove the caffeine. The green beans are soaked and then subjected to high pressure C02. The gas works as a solvent (like above) and removes the larger caffeine particles while leaving the smaller molecules behind. The caffeine is later removed from the C02 through a carbon filter. The gas can then be reused. This is a cheaper way of doing things, and less risky than the solvent method.

SUPERcritical carbon dioxide

So there are the three main ways that the coffee beans can be decaffeinated. However, if you can handle it I would recommend caffeinated coffee, as there is less damage done to the flavours. Also, the decaffeination process changes the beans to a brown colour, which makes it more difficult for the roasters to know when they are done.

Hope you enjoyed learning about the decaffeination process – see on Friday for the next post!!

Sunday mornings. They can be hectic – rushing around trying to get your last-minute errands done before the new week starts, or they can be chill and relaxing – the calm before the weekly chaos begins again. However, you spend it I think we can agree that a coffee in hand makes it a more pleasant experience.

Have you ever thought of how much your Sunday coffee is impacting the environment though? To the outside eye your takeaway coffee cup just looks a paper outside and plastic lid – however there are more sinister things lurking beneath the surface. The inner lining of the cup is made of polyethylene plastic which can’t be recycled in New Zealand and so means every single take away cup you ever have had is on a landfill, as it becomes too costly to remove the plastic away from the paper.

There is now a move to make your takeaway cups compostable instead. Most of the cup will be made of plant material instead. For example ecoware uses a plastic that is made from sugarcane or corn starch. These plastics (polylactic acid or polylactide) are not only biodegradable but also come from a renewable source. However, these cups can still not be recycled.

Compostable and and biodegradable mean different things too, so be careful and keep this in mind when companies market their products.

Biodegradable: Can be broken down quickly by microbes. It has also seen that plastics in landfills release methane gas which is contributing to global warming (which is 100% true, no matter what the FAKE NEWS says.)

It can be hard to guarantee that the café you visit has these compostable cups though, so if you want to take matters into your own hands you can always buy a reusable cup.

I recently purchased a cup off http://nz.keepcup.com/ and love it!! The site allows you to pick your own colour scheme as well as picking from a range of types and colours. These cups are also made of fully recyclable materials so can be shipped off at the end of its life (which is apparently 3 years +). During these 3 years, you alone would have contributed 2.7 kgs of plastic to the landfill. The only downside of these is carrying them around – but are fine if you know in advance you are getting a drink.

Baristas are always happy to use other cups (it makes less dishes for them) 👍

Another alternative is always to take a break and sit down and enjoy a nice ol’ fashioned have here coffee.

Happy drinking friends! Hope you are now enlightened to the effects of your weekly coffee cups. 😀

Last week we talked all about the science of milk, this week we are moving onto the other important ingredient in coffee – the espresso shot.

The shot is one of the vital parts of the drink. Messing this up will either leave you with a sour or bitter taste in your mouth (good milk can cover this up but only so much).

The shot process begins by grinding the beans into one of the portafilters.

The portafilter is what sits in the machine and what the shot pours out of.

The actual grind (how big or small the individual coffee grinds are) of the beans can be adjusted into different levels of coarseness through the grinder.

When the espresso shot pours it will take a certain amount of time. The ideal for this is 25-30 seconds. As the water comes down on the grinds (at about 130 pounds of force) it extracts the flavours from the grinds. However, if it is not timed right this will ruin your coffee shot.

If the shot pours too quickly then as the water runs through it does not absorb the oils or flavours in the coffee and you are left with a weak, thin espresso which tastes sour.

However, if the shot pours for too long then it is because the water sticks around for longer than it should, as it can’t get passed to the desired escape route of the coffee cup. This causes it to absorb not only the flavour but also other undesirable chemicals leaving it tasting strong and bitter.

A shot is poured

The best way to fix the extraction time is to change the grind. Water will have to force its way through a fine grind, making it take longer whereas water can rush through a coarser grind much faster. If you imagine a container of rocks and a container of sand – it takes the water a lot longer to get through the sand than the rocks as there is less space for it to get through.

It is easier for liquid to pass through larger, more coarse objects.

You can also adjust your tamping pressure as well. Tamping provides a nice flat compact bed of coffee for the water to hit and compresses the coffee grinds. A harder tamp will compact more, meaning a longer extraction time.

Tamping allows the water to hit a compact, flat surface.

Coffee extraction in its 3 stages

Dark thin trickle with a strong aroma, flavour and colour that is released into the shot.

The caffeine and other bitter compounds begin to be extracted from the grinds.

Stream lightens in colour and then the more unpleasant, more bitter acids begin to be extracted.

So next time you get your coffee and it tastes bitter or sour – or just not quite right, you now know why! (I don’t know if that will make you feel better about it or not though).